#include "bits/stdc++.h"
using namespace std;
#define ff first
#define ss second
#define ll long long
#define SZ(s) (int)s.size()
const int N = 2e5 + 5;
vector <pair <int, int>> v[N];
ll dp[N][2], ans = 0, dp1[N][2], vis[N], kk[N];
multiset <ll> st[N];
void f(int x, int y) {
vector <pair <int, int>> v1;
ll w = 0, s = 0, s1 = 0;
for(auto i : v[x]) {
if(i.ff == y) {
w = i.ss;
continue;
}
f(i.ff, x);
v1.push_back({i.ff, i.ss});
s += max(dp[i.ff][0], dp[i.ff][1]);
}
dp[x][0] = dp[x][1] = s;
for(int i = 0; i < SZ(v1); i++) {
int a = v1[i].ff, wa = v1[i].ss;
dp[x][1] = max(dp[x][1], w + s - max(dp[a][0], dp[a][1]) + dp[a][0] + wa);
}
}
void fn(int x, int y, int ww) {
if(!vis[y]) {
for(auto [i, w] : v[y]) {
kk[y] += max(dp1[i][0], dp1[i][1]);
st[y].insert(dp1[i][0] + w - max(dp1[i][0], dp1[i][1]));
}
while(SZ(st[y]) > 2) st[y].erase(st[y].begin());
vis[y] = true;
}
bool tr = 0;
dp1[y][1] = dp1[y][0] = kk[y] - max(dp1[x][0], dp1[x][1]);
if(st[y].find(dp1[x][0] + ww - max(dp1[x][0], dp1[x][1])) != st[y].end()) st[y].erase(st[y].find(dp1[x][0] + ww - max(dp1[x][0], dp1[x][1]))), tr = 1;
if(SZ(st[y]) > 0) dp1[y][1] = max(dp1[y][1], ww + kk[y] - max(dp1[x][0], dp1[x][1]) + *st[y].rbegin());
if(tr == 1) st[y].insert(dp1[x][0] + ww - max(dp1[x][0], dp1[x][1]));
ll k = 0;
for(auto [i, w] : v[x]) {
k += max(dp1[i][0], dp1[i][1]);
}
ans = max(ans, k);
for(auto [i, w] : v[x]) {
if(i != y) fn(i, x, w);
}
dp1[y][0] = dp[y][0];
dp1[y][1] = dp[y][1];
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(nullptr);
int n;
cin >> n;
for(int i = 1; i < n; i++) {
int a, b, c;
cin >> a >> b >> c;
v[a].push_back({b, c});
v[b].push_back({a, c});
}
f(1, 0);
for(int i = 1; i <= n; i++) {
dp1[i][0] = dp[i][0];
dp1[i][1] = dp[i][1];
}
fn(1, 0, 0);
cout << ans;
return 0;
}
